Arsenic pentachloride

Arsenic pentachloride is a chemical compound with the formula AsCl₅. It is a yellow solid that is highly reactive and is known for its instability at room temperature. Arsenic pentachloride is of interest primarily in the field of inorganic chemistry and is used in research settings.

Structure and Properties

Arsenic pentachloride is a molecular compound that consists of one arsenic atom surrounded by five chlorine atoms. The geometry of the molecule is trigonal bipyramidal, which is typical for compounds with five ligands around a central atom. The compound is known to decompose at temperatures above 300 °C, releasing chlorine gas and forming arsenic trichloride (AsCl₃).

Synthesis

Arsenic pentachloride can be synthesized by the direct chlorination of arsenic trichloride (AsCl₃) at low temperatures. The reaction is as follows:

AsCl₃ + Cl₂ → AsCl₅

This reaction must be carried out under controlled conditions to prevent the decomposition of the product.

Reactions

Arsenic pentachloride is a strong oxidizing agent and can react with a variety of substances. It is known to react with water to form arsenic acid and hydrochloric acid:

AsCl₅ + 4H₂O → H₃AsO₄ + 5HCl

Due to its reactivity, arsenic pentachloride is used in some chemical syntheses and research applications.

Safety and Handling

Arsenic pentachloride is highly toxic and should be handled with extreme care. It is corrosive and can cause severe burns upon contact with skin. Proper protective equipment, such as gloves and goggles, should be used when handling this compound. It should be stored in a cool, dry place, away from moisture and incompatible materials.

Applications

While arsenic pentachloride is not widely used in industry, it is of interest in academic research. It is used as a reagent in the synthesis of other arsenic compounds and in studies of inorganic chemistry.

Also see

• Arsenic trichloride
• Arsenic acid
• Chlorine
• Inorganic chemistry